科尔沁沙地外来入侵植物光梗蒺藜草的种子库分布格局

Distribution pattern of seed band for alien invasive species of Cenchrus incertus

在通辽市科尔沁区的固定沙地,半流动沙地采用相邻样方法观测光梗蒺藜草已萌发种子和未萌发种子在不同埋深中的分布,发现在固定沙地中,光梗蒺藜草种子分布在埋深较浅处(0～3cm),集中分布在0～1cm;在半流动沙地中,光梗蒺藜草种子分布较为分散,在1～15cm埋深处均有分布,在埋深0～5cm处种子数量较多。固定和半流动沙地中光梗蒺藜草种子随着埋深增加出苗率也随之增加,可达到100%。负二项式法和方差/均值比率(分布系数)法一致的验证了光梗蒺藜草苗和土壤种子库的种子种群分布格局为集群分布。光梗蒺藜草自然散布距离很短,是造成其种群集聚分布格局的原因。

The investigation of distribution pattern of soil seed bank of Cenchrus incertus showed that the seeds of Cenchrus incertus mainly distribute in the soil of 0-3 cm depth.Most seeds are gathered in the soil of 0-1 cm depth in fixed sandy land.Seeds of C.incertus disperse in 1-15 cm depth in semi-mobile dune,and most seeds exist in 0-5 cm.With the depth increase,the germination rate increases in fixed and semi-moble sandy area.The negative binominal formula and the ratio of variance and mean（distribution coefficient） proved the distribution pattern of seed population is cluster distribution.The seed natural disperse distance resuts in the centralizing distribution pattern for the species.